Visualizing Plasmon Coupling in Closely Spaced Chains of Ag Nanoparticles by Electron Energy-Loss Spectroscopy
Visualizing Plasmon Coupling in Closely Spaced Chains of Ag Nanoparticles by Electron Energy-Loss Spectroscopy
复制标题
通过电子能量损失光谱可视化银纳米粒子的紧密间隔链中的等离激元耦合
DOI：
10.1002/smll.200901639
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发表时间：
2010-02-05
期刊：
影响因子：
13.3
通讯作者：
Wang, Guanghou
中科院分区：
文献类型：
--
作者：
Song, Fengqi;Wang, Tingyu;Wang, Guanghou
使用扫描透射电子显微镜中的电子能量损失谱，可以观察到银纳米颗粒紧密排列链中的各向异性等离子体激元耦合。对于作为最简单的链的二聚体，映射的等离子体激元激发与纳米空间分辨率和0.27 eV的能量分辨率直观地确定两个耦合等离子体激元。随着粒子间距的减小，同相模式从紫外区红移，在2.7 eV处达到可见光范围。基于离散偶极近似的计算证实了它的光学活性，其中纵向方向被构造为光传输的路径。然后在内折的四粒子链中观察到两条耦合路径。
Anisotropic plasmon coupling in closely spaced chains of Ag nanoparticles is visualized using electron energy-loss spectroscopy in a scanning transmission electron microscope. For dimers as the simplest chain, mapping the plasmon excitations with nanometer spatial resolution and an energy resolution of 0.27 eV intuitively identifies two coupling plasmons. The in-phase mode redshifts from the ultraviolet region as the interparticle spacing is reduced, reaching the visible range at 2.7 eV. Calculations based on the discrete-dipole approximation confirm its optical activeness, where the longitudinal direction is constructed as the path for light transportation. Two coupling paths are then observed in an inflexed four-particle chain.